Patriot's Day: 5 things you should know

Actors depicting British troops prepare to charge a line of Colonial Revolutionary War militiamen on April 15, 2013, during the annual Patriot's Day performance of the 1775 Battle of Lexington on the town green in Lexington, Mass.(Photo: Ann Ringwood, AP)

Monday is Patriot's Day, commemorating the Battles of Lexington and Concord, and the start of the American Revolution. USA TODAY Network explains what the holiday is all about.

1. What's the significance of the day?

The American Revolution would prove to be a defining event in world history, and April 19, 1775, was "unquestionably the day it all began," said David Wood, curator of the Concord Museum, in an interview with USA TODAY Network.

The holiday is celebrated on the third Monday of April, despite the date.

2. What actually happened on this day?

On the night of April 18, 1775, about 700 British troops stationed in Boston set out for Concord, Mass., approximately a 20-mile march, to seize military supplies. It was rumored the stockpiles in town could arm 15,000 colonists, Wood said.

Early in the morning on April 19, on the way to Concord, the soldiers encountered colonial militiamen in Lexington and fired upon them, killing eight. The British troops "actually gave a cheer and moved on to Concord," Wood said.

In Concord, the first shots fired by the colonists against the British occurred on North Bridge. The phrase "shot heard 'round the world" — a line from Ralph Waldo Emerson's 1837 poem, Concord Hymn — refers to the gunfire exchanged in that town.

The British retreated back to Boston and were "on the road for 15 hours and under fire almost continually," Wood said.

An actor portraying a British officer prods an actor portraying a fallen member of the colonial militia during the annual Patriot's Day reenactment in Lexington, Mass. This photo was taken in 2006.(Photo: Josh Reynolds, AP)

3. Who were the Minutemen?

In colonial times, all able-bodied men ages 16-60 had to keep a gun and serve in a part-time citizen army called the militia.

A commonly held myth is the Minutemen consisted of "ragtag farmers who happened to pick up guns and face the greatest army on Earth," Sideris said.

In reality, they were trained more frequently than the general militia and could be deployed "at a minute's warning," according to the park's website. Their "bag was always packed and gun always ready," Sideris said.

When the British marched to Concord, the Minutemen and militiamen of Lexington and Concord came to the call, as did militias from more than 50 other communities, Wood said.

4. Who was Paul Revere?

Revere was a Boston silversmith who warned the Lexington Minutemen of the approaching British troops. He is memorialized in Henry Wadsworth Longfellow's poem Paul Revere's Ride, with the famous line, "One if by land, and two if by sea."

The alerts were so effective that by the time the British reached Charlestown outside of Boston, 5,000 to 7,000 militia members had surrounded them, Wood said.

"That really speaks of commitment, the organization, the deliberation. This was not an accident," Wood said.

5. How do people celebrate Patriot's Day today?

Patriot's Day will take on added significance this year with the running of the Boston Marathon a year after the bombings that killed three people and injured more than 250. The marathon is always held on Patriot's Day.

Historical re-enactments occur every year on April 19 at Minute Man National Historical Park. And parades are held in Lexington, Concord and other towns.

Patriot's Day is a public holiday in Massachusetts and Maine, which was part of the Massachusetts Bay Colony.

"July 4 is the nation's celebration, but Patriot's Day really belongs to this area," Wood said.